expansion error

[09:36:51] [Craft Scheduler Thread - 1842/WARN]: [Slimefun] Plugin Slimefun vDEV - 408 (git 73b64e87) generated an exception while executing task 73
java.lang.NoClassDefFoundError: io/github/thebusybiscuit/cscorelib2/materials/MaterialCollections
	at me.john000708.slimexpansion.machines.DeepDepthMiner.tick(DeepDepthMiner.java:223) ~[?:?]
	at me.john000708.slimexpansion.machines.DeepDepthMiner$2.tick(DeepDepthMiner.java:134) ~[?:?]
	at me.mrCookieSlime.Slimefun.api.TickerTask.run(TickerTask.java:130) ~[?:?]
	at me.mrCookieSlime.Slimefun.SlimefunPlugin.lambda$onEnable$1(SlimefunPlugin.java:283) ~[?:?]
	at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftTask.run(CraftTask.java:84) ~[patched_1.15.1.jar:git-Paper-60]
	at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:54) ~[patched_1.15.1.jar:git-Paper-60]
	at com.destroystokyo.paper.ServerSchedulerReportingWrapper.run(ServerSchedulerReportingWrapper.java:22) ~[patched_1.15.1.jar:git-Paper-60]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_232]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_232]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_232]
Caused by: java.lang.ClassNotFoundException: io.github.thebusybiscuit.cscorelib2.materials.MaterialCollections
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[?:1.8.0_232]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:139) ~[patched_1.15.1.jar:git-Paper-60]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:85) ~[patched_1.15.1.jar:git-Paper-60]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_232]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_232]
	... 10 more